Plumb bob



Jan. 28, 1930. J. T. OXFORD,

PLUMB BOB Filed Sept. 25, 1927 71 .W 7 8 0 f/ Mu Patented Jan. 28, 1930 UNITED STATES JOHN T. OXFORD, OF MORGANTON, NORTH CAROLINA PLUMIB: BOB

Application filed September 23, 1927.

This invention relates to improvements in plumb-bobs, and .has for one of its objects to provide a two in one plumb-bob.

Another object of the invention is to provide a plumb-bob so constructed that it will quickly come to a plumb position.

Another object of the invention is to provide a plumb-bob with a removable core having a reduced tapered shank or indicating point.

A further object of the invention is to provide a combined plumb-bob and gauge whereby a user may determine the exact distance the plumb-line is from the surface being plumbed.

A still further object of the invention is to provide the combination of a plumb-bob and a gauge therefor, the hob and gauge being of the exact same diameter.

Another object of the invention is to provide in a plumb-bob having a removable core, means whereby they may be held frictionally together.

With the above and such other objects in view as may hereinafter more fully appear,

I have invented the device illustrated in the accompanying drawings, in which:

Figure 1 is an elevational view of my improved plumb-bob, shown in operative position;

Figure 2 is adetail perspective view of a plumb-bob body;

Figure 3 is a similar view of a core member;

Figure 4: is a plan view of a gauge member;

Figure 5 is an end view of a core shown in Figure 3; V

Figure 6 is an elevational view of the plumb-bob core shown in use in a corner;

Figure 7 is a section on line 7-7 of Figure 1, showing the manner of holding the plumbbob and its core connected together.

Like reference characters indicate like parts throughout the following specification and in the several views in the drawings, in which 1 indicates a plumb-bob the body 2 of which having a vertical central bore 3 with which a removable core 4 is associated, said core being of a length to project a sub- Serial No. 221,480.

stantial distance from each end of body 2, the lower end 5 of which'being reduced toa relatively small diameter and tapered to the point '6. The said core 4 is made preferably of tool steel in order that thepoint 6 will remain pointed a very much longer time than the plumb bobs of common construction. Furthermore, as the core is easily removable by merely pressing its upper end 7 withthe thumb, its point can be more readily ground when it becomes dull, as the body 2 is not in the way for the grinding operation. The body 2 is made preferably of brass, or some other non-magnetic material in order that the plumbing operation will not be materially affected through any magnetic influence. This body 2 is so formed that the bulk of its weight is adjacent its lower end, the bottom taper 8 of the body 2 being at a much'more acute angle'than the upper elongated tapered portion 9, the latter taper terminating in a reduced cylindrical collar 1O. The bore 3 in body 2 is slightly tapering at its lower end as indicated at 11 and the portion of the core 1, just above the flange 15 thereof is tapered as at'l i, to wedgingly fit into the tapered portion 11. The flange 15 on the member 4 at its lower end forms a stop to prevent the core'l from wedging too tightly in said bore. The upper end 7 of the core 1 is provided with a central vertical bore 17 which meets the side horizontal bore 18 to receive the knotted end of the plumb-line 19, the upper end of .which extends through a bore 20 in the disk 21 the diameter of which is identical with thatof the large cylindrical portion 22 of said body 2.

The hole in the gauge is one-thirty-second larger than the hole in the spike of the plumb-bob. This disk is the same diameter as 9 the body of the plumb-bob and is A thick.

The radius of the gauge 21 and plumb-bob 2is stamped on both, so that the workman will know exactly how far away his line 19 or center point is from the outer wall 22 of the plumb-bob.

The purpose of the plumb-gauge, in connection with the plumb-bob is to enable the workman to determine exactly how far away his center line and point 6 of the core 4 are from the object being plumbed.

For example, when plumbing a vertical shaft the gauge is held horizontal with its edge against the shaft 23 and the cord drawn to the side of the hole 20 away from the shaft, the plumb-bob will hang slightly away from the shaftwhen the shaft is plumb.

If the body of the plumb-bob were to touch the shaft one could not tell if the shaft was plumb. For this reason the hole 20 is drilled one-thirty-second larger in the gauge 20 than the bore 17 in core 4, so that the plumb-bob will hang perfectly free and allow one to see a space between the wall of the plumb-bob and the object being plumbed. This insures greater accuracy as it is absolutely dependable and is a great time saver.

As indicated in Figure 6 the core 4 can be used as a plumb-bob independently of its body 2, in close corners or places where it would be inconvenient or impossible to use a bob of greater diameter.

Having now described my invention, that which I claim as new, and desire to procure by Letters Patent, is:

1. A plumb-bob and a plumb-gauge therefor, said gauge comprising a disk of the same diameter as the largest diameter of the plumb-bob, and means whereby the plumbob, when suspended from said gauge disk, will hang eccentrically relative thereto.

2. The combination with a plumb-bob, and line on which it is suspended, of a gauge member having an opening through which said line may pass, the distance from said opening to the working edge of said gauge member being substantially equal to the maximum radius of said bob.

3. The combination with a plumb-bob, and line on which it is suspended, of a gauge member having an opening through which said line may pass, the distance from said opening to the working edge of said gauge member being substantially equal to the maximum radius of said hob, and said opening being substantially larger than said line, whereby, when said gauge is placed in con tact with an object to be plumbed, and the line drawn over to the side of said opening opposite said object, said bob will just clear said object when plumb.

4. The combination with a plumb-bob, and line on which itis suspended, of a gauge member in the form of a disk, said disk being of a diameter equal to the maximum diameter of said bob, and having a central opening through which said line may pass.

In testimony whereof I atfix my signature.

JOHN T. OXFORD. 

